Growing up, Tom O'Halleran was taught the value of hard work and honesty in serving his community. He took these lessons and joined the Chicago Police Department where he was commissioned as one of the youngest homicide detectives in the city's history. He served with distinction, receiving countless commendations and awards for his work to serve and protect his community.

Following his service, Tom became a member of the Chicago Board of Trade and opened his own small business. As a member of the board of directors, he chaired the finance, floor operations, and planning committees. His work gave the Board of Trade a vision for the future.